Container with corner window and blank therefor



April 12, 1966 c. E. PALMER 3,245,526

CONTAINER WITH CORNER WINDOW AND BLANK THEREFOR Filed Nov. 7 29, 1963 INVENTOR. CHARLES E. PALMER United States Patent a Company, St. Louis, Mo., a corporation of Delaware Filed Nov. 29, 1963, fier. No. 326,639 12 Claims. (Cl. 206-4531) The present invention relates to window containers and more specifically to a novel window container having a transparent corner portion and the blank therefor.

In marketing various packaged articles it is often highly desirable, and in certain instances mandatory under law, to have a list of ingredients or a label visible from the ex terior of the package. This is particularly true of instances wherein a plurality of small labeled containers of drugs are packed in a larger container for shipping and storage. To avoid duplication of labelling on the exterior of the larger container, it is desirable to provide a window therein registering with a label on one of the smaller containers. However, this window must generally expose more than one surface of the contents to enable viewing of all the desired information. Similarly, windows in more than one side of the containers are desirable for viewing various surfaces of other types of contents or for inventorying the contents without opening the container.

It is an object of the present invention to provide an attractive and relatively economical container having a window extending about a corner into a multiplicity of wall panels and which is substantially dust proof along all the edges of the window.

Another object is to provide such a container wherein one of the Windowed panels may be repeatedly opened and closed while leaving intact the desirable dust-proof charatceristics of the window construction.

It is also an object to provide a relatively simple and economical blank for such a container having a window of semi-rigid synthetic plastic sheet material extending about a corner into three panels.

A further object is to provide such a blank which may be conveniently and readily folded into such a container and which is simply and economically manufactured.

Other objects and advantages will be readily apparent from the following detailed specification and the attached drawings wherein:

FIGURE 1 is a perspective view of a container embodying the present invention;

FIGURE 2 is a fragmentary perspective view of the other side of the container of FIGURE 1 with the container opened for clarity of illustration;

FIGURE 3 is a view similar to FIGURE 2 illustrating the operation of the folding window portion during closure; and

FIGURE 4 is a plan view to a reduced scale of the blank for the container of FIGURES 1-3.

It has now been found that the foregoing and related objects may be readily attained in a polygonal container having a transparent window portion at a corner thereof with a frame of relatively rigid and opaque sheet material with a plurality of wall panels defining the several sides thereof. Three edge lines at the junctures between adjacent wall panels converge toward one corner of the container and a window aperture in the frame extends into the wall panels which meet at the converging edge lines. A window of semi-rigid synthetic plastic sheet material has three edge fold lines therein in general alignment with the converging edge lines and meeting at the one corner of the container. The window also has two diverging adjacent plait fold lines extending from the corner between two adjacent edge fold lines to the margin thereof and providing a plait therein. The window edge fold lines substantially conform with the configuration of the portion of the container adjacent the one corner. Marginal portions of the frame adjacent the window aperture overlap the corresponding side margins of the window, and the window is secured to the frame along the overlapping marginal portions by suitable means permitting free folding of the plait.

Although the container may have various polygonal configurations, a rectangular body having three mutually adjacent panels defining the windowed corner is preferably and most conveniently employed. One of the apertured panels is desirably a hinged closure wall panel in which case the plait folds and unfolds with the closing and opening of the container. This construction provides for repeated opening and closing of the container without destroying the substantially dust-proof character of the window and windowed corner. In this closure-type construction, a window support flap is preferably hingedly connected to one of the adjacent wall panels and underlies the closure wall panel. This flap has the window aperture extending thereinto and supports the plaited window.

The window may be secured to the frame by various means including mechanical locks or fingers but preferably is adhesively bonded thereto either by an interposed coating of a separate adhesive or by solvent or heat-activation of the plastic sheet material to render it adherent to the paperboard. The adhesive or other securing means should permit free folding of the plait and generally should be absent from the overlapping marginal portions between the plait fold lines.

The container of the present invention is formed from a blank utilizing a frame of relatively rigid and opaque sheet material having weakening lines therein defining fold lines and a plurality of wall panels adapted to be folded about the fold lines to form the several sides of the erected container. The margins of three adjacent wall panels converge toward a point and are adapted to define one corner of the erected container and the frame has a window aperture therein extending about this point into the three adjacent wall panels. The blank further includes a window of semi-rigid synthetic plastic material of larger dimension than the window aperture with marginal portions of the frame about the aperture overlapping the corresponding side margins of the Window.

The window has weakening lines therein defining three edge fold lines in general alignment with the converging panel margins and meeting at the aforementioned point of convergence. The window also has weakening lines therein between adjacent edge fold lines which define two diverging adjacent plait fold lines extending from the point of convergence to the margin thereof to provide a plait upon folding of the container blank and window and to form a transparent corner portion in the erected container. The window is secured by suitable means to the frame along the marginal portions to permit free folding of the plait.

Preferably, the weakening lines defining the edge fold lines in the window'are provided by scoring on its inner surface to a sufiicient depth to permit folding while leaving the outer surface of the Window smooth and unbroken. However, it is possible to provide perforations along the weakening lines with the attendant loss in strength and appearance. Exposed plait fold lines should also be scored on the inner surface to maintain a smooth and unbroken outer surface on the window. The score lines conveniently are made in the window material in accordance with the teachings of applicants copending application Serial Number 312,564 entitled Apparatus and Method for Scoring Synthetic Plastic Sheet Material and filed September 30, 1963. In that application, applicant teaches means of scoring plastic sheet material to a predetermined uniform depth.

Turning now in detail to the attached drawings, FIG- URE 4 illustrates a blank for the polygonal container of FIGURES l-3 embodying the present invention. Generally the blank and container are comprised of an integrally formed frame of relatively rigid and opaque sheet material, generally designated by the numeral 2, and a window 4 integrally formed from synthetic plastic sheet material.

As best seen in the blank of FIGURE 4, the frame is provided with longitudinally extending score or weakening lines 6 and transversely extending weakening lines 8 defining the several fold lines made in erecting the blank and the resultant wall panels and flaps. More particularly, the weakening lines 6, define bottom wall panel It), front wall panel 12, hingedly connected to the front edge of the bottom wall panel 10, a top wall panel 14, hingedly connected to the top edge of the front wall panel 12, and a tuck flap l6 hingedly connected to the rear edge of the top wall or closure panel 14. Side wall panels 18, 20 are hingedly connected to the side of front wall panel 12, and rear wall panel 22 is hingedly connected to the rear edge of side wall panel 20. The free end of rear wall panel 22 is provided with a glue flap 24 for engagement with side wall panel 18, and side wall panels 18, 24 are provided with glue flaps 26, 28 for engagement with bottom Wall panel to lock the container in erected position. Side wall panels 18, are also provided with hingedly connected dust flaps 3t), 32 respectively.

Hinge lines or margins of front wall panel 12, top wall panel 14, and side wall panel 20, as well as that of the dust flap 32, converge toward point p which forms a corner of the erected container. A generally rectangular window aperture 34 extends about point p into front wall panel 12, top wall panel 14, and wall panel 20, and into the dust flap 32, which also functions in the illustrated embodiment as a window support flap.

As seen in the drawings, the aperture 34 is of lesser dimension than the window 4 and marginal portions of the frame 2 adjacent the aperture 34 overlap the corresponding margins of the window 4'. The window 4 is provided with score or weakening lines therein defining three edge fold lines 36, 38 and 4A) which are generally aligned with the aforementioned converging margins and meet at the point p. The window 4 also has weakening lines defining two diverging adjacent plait fold lines 42, 44 extending from the point p away from or outwardly from the front wall panel 12 and the side wall panel 2t) to the margin of the window 4 between adjacent edge fold lines 36, 38. Plait fold line 4-4 is in general alignment with the hinged fold line 40 between the front wall panel 12 and the side wall panel 20. The window 4- is secured to the frame 2 along the marginal portion thereof by well known means such as interposed adhesive indicated by the numeral 46 except for that portion between the plait fold lines 42, 44 to permit free folding of the plait.

The folding of the window 4 and plait is best seen in FIGURES 2 and 3. In FIGURE 2, the container is in erected position with the top wall panel 14 and window support flap 32 in open position for inserting or removing contents. In this position, the window 4 is folded along edge fold line 4t) and plait fold line 44. In FIG- URE 3, the window support flap 32 has been folded into closed position which folds the window 4 about edge fold line 38 and folds the window 4 back upon itself at plait fold line 42, the unsecured portion of the window 4 between plait fold line 42 and 44 being drawn away from top wall panel 14. When the top wall or closure panel 14 is closed as seen in FIGURE 1, the window 4 is folded about edge fold line 36 and plait fold line 44 to complete the forming of a plait, resulting in an attractive, transparent corner portion conveniently folded from a single semi-rigid piece of plastic sheet material during the erection and closing of the container.

In the illustrated embodiment, the plait is folded to lie on the outer surface of the remainder of the window 4, with plait fold line 42 visible and extending diagonally across the portion of the window in the top surface of the container where it is relatively free from risk of snagging. The window support fiap 32 reinforces the portion of the window 4 therewith against inward pressure resulting from any tendency of the plait to partially unfold.

If the entire portion of the window 4 overlain by the marginal portion of the top wall panel 14 in the blank is left unsecured thereto, the plait may be folded to lie inwardly of the window, thereby hiding the diagonally extending plait fold line 4-2 beneath the window 4. In this case, the plait will open along the front edge of the top wall panel 14 and may be subject to snagging.

As a further alternative, the edge of the window support flap 32 adjacent the top wall panel 14 may be hingedly connected thereto, and the window 4 may be adhered to the frame 2 about its entire periphery. Plait fold line 42 is removed from the top wall portion of the window and extends diagonally across the portion of the Window 4 associated with window support flap 32 and continues across the support flap. In this manner, a plait is formed both in window support flap 32 and the portion of the window 4 associated therewith.

Although the drawings illustrate a rectangular container, the present invention is equally applicable to any polygonal container in providing a transparent corner portion formed from a single piece of plastic sheet material which folds into position with the erection and closing of the container. The windowed corner will generally be formed by three meeting surfaces, but the in vention can provide a folding corner window from a fiat sheet of material for corners formed by a greater number of meeting surfaces.

In a container having the windowed corner defined by three or more panels, the fiat sheet of window material extends 360 degrees about the corner point p. The plait can be adapted to remove a ray of sheet material from the full 360 degrees, leaving an angular amount equal to the sum of the angles between adjacent panel edges and edge folds lines in the erected container. Because the sheet material of the plait is doubled, the angle of divergence between the plait fold lines is half the angle of the ray to be removed, or equal to (360-S)/2, where S is the sum of the angles between adjacent panel edge lines defining the windowed corner in the erected container.

The frame may be readily fabricated from paperboard sheet material of about 12 to 15 mils in thickness to provide ample rigidity for this purpose. If desired, the paperboard may be dyed or printed readily, making possible wide variations in appearance of the container.

The synthetic plastic sheet material employed for the window should be semi-rigid with sufficient flexibility to accommodate stresses and impacts occurring during normal usage.

Exemplary of the various synthetic plastic sheetings which may be employed are biaxially oriented polystyrene, cellulose acetate, cellulose acetate butyrate, polyvinyl chloride-acetate copolymer, polyethylene and polypropylene. As a specific example of a highly advantageous material, biaxially oriented polystyrene of about 4 to 12 mils has been particularly effective because of its clarity, high strength and semi-rigidity coupled with sufficient resiliency and flexibility to provide durable folds and resistance to normal impacts.

Thus it is seen that the present invention provides an attractive container having a corner window folded from an integral piece of plastic sheet material. The container may be repeatedly opened and closed without destroying the integrity of the window which is substantially dustproof along all edges thereof. The container of the present invention is readily folded from a relatively simple and economical blank having an integral frame and an integral window.

Having thus described my invention, I claim:

1. A polygonal container having a transparent window having an aperture extending about said one corner into the wall panels joining at said edge lines; a window integrally formed from semi-rigid synthetic plastic sheet material having three edge fold lines therein in general alignment with said three edge lines of the frame and meeting at said one corner of said container, said window having two diverging adjacent plait fold lines therein extending from said one corner between two adjacent edge fold lines therein to the margin of said window and providing a plait, said window edge fold lines substantially conforming to the configuration of the portion of the container adjacent said one corner, said frame having marginal portions adjacent said aperture overlapping the corresponding side margins of said window; and means securing said window to said frame along said marginal portions and permitting free folding of said plait.

2. The container of claim 1 wherein the outer surface of said window is smooth and unbroken.

3. The container of claim 1 wherein said one of said apertured wall panels is a closure panel, said plait unfolding when said closure panel is opened and folding when said closure panel is closed to provide a substantially dust proof closure about said window.

4. The container of claim 1 wherein said relatively aural; pres .IQIIlElHOO on], go louroo ouo pie/n01 fiurfileAuoo rigid and opaque sheet material is paperboard, and wherein said synthetic plastic sheet material is biaxially oriented polystyrene of about 4 to 12 mils in thickness.

5. The container of claim 1 wherein said means securing said window to said frame is adhesive and the overlapping marginal portions between said plait fold lines are free from adhesive.

6. A six-sided container having a transparent window portion at a corner thereof comprising a frame of relatively rigid and opaque sheet material having front, rear, top, bottom and side wall panels, said top wall panel being hingedly connected to said front wall panel along the top edge thereof to provide a closure for the container and said frame having a window support flap hingedly connected to one of said side wall panels along the top edge thereof and underlying said top wall panel, said top portion at a corner thereof comprising a frame of relatively rigid and opaque sheet material with a plurality of wall panels defining the several sides thereof, threee edge lines at the junctures between adjacent wall panels wall, front wall and one side wall panels converging toward one corner of said container, said frame having an aperture therein extending about said one corner into said top wall, front wall, and one side wall panels and into said window support flap; a window integrally formed from semi-rigid synthetic plastic sheet material and having three edge fold lines in general alignment with the hinged edge lines of said one side and top wall panels and the juncture of said front and one side wall panels and meeting at said one corner of said container, said window having two diverging, adjacent plait fold lines extending from said one corner between said hinged edge fold lines, one of said plait fold lines being in general alignment with said hinged edge line of said top wall panel, said plait fold lines extending to the margin of said window and said window having a plait therein defined by said plait fold lines, and said window edge fold lines substantially conforming to the configuration of the portion of the container adjacent said one corner, said frame having marginal portions adjacent said aperture overlapping the corresponding side margins of said window, said plait unfolding with the opening of said top wall panel and folding with the closing thereof to provide a substantially dust proof closure about said window, said window support flap tending to maintain said plait; and means securing said window to said frame along said marginal portions and permitting free folding of said plait.

7. The container of claim 6 wherein the outer surface of said window is smooth and unbroken.

8. The container of claim 6 wherein said means securing said window to said frame is adhesive and the overlapping marginal portions between said plait fold lines are free from adhesive.

9. A blank for a polygonal container having a transparent window portion at a corner thereof comprising a frame of relatively rigid and opaque sheet material, said frame having weakening lines therein defining fold lines and a plurality of wall panels adapted to be folded about fold lines to form the several sides of the erected container, the margins of three adjacent wall panels converging toward a point and adapted to define one corner of the erected container, said frame having a window aperture extending about said point into said three adjacent wall panels; a window of semi-rigid synthetic plastic material of larger dimension than said window aperture with marginal portions of said frame about said aperture overlapping the corresponding side margins of said window, said window having weakening lines therein defining edge fold lines in general alignment with said panel margins and meeting at said point, said window also having weakening lines therein defining two diverging adjacent plait fold lines extending from said point between two adjacent edge fold lines to the margin thereof to provide a plait upon folding of said container blank and window and form a transparent corner portion in the erected container; and means securing said window to said frame along said marginal portions and permitting free folding of said plait.

10, The blank of claim 9 wherein the outer surface of said window is smooth and unbroken.

11. The blank of claim 9 wherein said relatively rigid and opaque sheet material is paperboard, and wherein said synthetic plastic sheet material is biaxially oriented polystyrene of about 4 to 12 mils in thickness.

12. A blank for a six-sided container having a transparent window portion at one corner thereof comprising a frame integrally formed of relatively rigid and opaque sheet material, said frame having weakening lines therein defining front, rear, top, bottom, and side wall panels, said top wall panel being hingedly connected to said front wall panel and adapted to provide a closure for the container, said frame having a window support flap hingedly connected to one of said side wall panels, the margins of said top wall, front wall and one side wall panels and said support flap converging toward a point adapted to define one corner of the erected container, said frame having a window aperture therein extending about said point into said top wall, front wall, and one side wall panels and into said window support flap; a window of semi-rigid synthetic plastic material of larger dimension than said window aperture with marginal portions of said frame about said aperture overlapping the corresponding side margins of said window, said window having weakening lines therein defining three edge fold lines in general alignment with said converging margins and meeting at said point of convergence, said window also having weakening lines therein defining two diverging adjacent plait fold lines extending from said point outwardly from said front and side wall panels to the margin thereof, one of said plait fold lines being in general alignment with the hinged fold line between said front and side wall panels to provide a plait upon folding of said container blank and Window and to form a transparent corner portion in the erected and closed container, said Window support flap tending to restrain the plait from unfolding in the erected and closed container; and means securing said Window to said frame along said marginal portions and permitting free folding of said plait.

No references cited.

THERON E. CONDON, Primary Examiner. 

1. A POLYGONAL CONTAINER HAVING A TRANSPARENT WINDOW HAVING AN APERTURE EXTENDING ABOUT SAID ONE CORNER INTO THE WALL PANELS JOINING AT SAID ONE CORNER INTO TEGRALLY FORMED FROM SEMI-RIGID SYNTHETIC PLASTIC SHEET MATERIAL HAVING THREE EDGE FOLD LINES THEREIN IN GENERAL ALIGNMENT WITH SAID THREE EDGE LINES OF THE FRAME AND MEETING AT SAID ONE CORNER OF SAID CONTAINER, SAID WINDOW HAVING TWO DIVERGING ADJACENT PLAIT FOLD LINES THEREIN EXTENDING FROM SAID ONE CORNER BETWEEN TWO ADJACENT EDGE FOLD LINES THEREIN TO THE MARGIN OF SAID WINDOW AND PROVIDING A PLAIT, SAID WINDOW EDGE FOLD LINES SUBSTANTIALLY CONFORMING TO THE CONFIGURATION OF THE PORTION OF THE CONTAINER ADJACENT SAID ONE CORNER, SAID FRAME HAVING MARGINAL PORTIONS ADJACENT SAID APERTURE OVERLAPPING THE CORRESPONDING SIDE MARGINS OF SAID WINDOW; AND MEANS SECURING SAID WINDOW TO SAID FRAME SALONG SAID MARGINAL PORTIONS AND PERMITTING FREE FOLDING OF SAID PLAIT. 